Process of making compound metal bodies.



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2 SHEETS-SHEET 1.

ATTORN EY WlTNESSES:

J. F. MONNOT.

PROCESS 0I' MAKING GOMPOUND METAL BODIES.

Arrnxonron Hmm 113.10, 1907. BENBWED un 5, 1910.

72,630, Patented 001;. 11,1910.

2 SHEETS-SHEET 2*.

v INVENTOR Mmw ATTORNEYS UNTTED sTATEs PATENT oEEIoE. j.

JOHN F. MONNOT, OF NEW YORK, N. Y., ASSIGNOB TO DUPLEX METALS COMPANY,OF

NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF MAKING COMPOUND METAL BODIES.

Bpeoioation o! Letters Patent.

Patented oct. 11, 1910.

Application led February 18, 1907, Serial No. 358,007. Renewed Hay 5,1910. Serial No. 559,483.

To all whom it may concern:

Be it known that I, JOHN F. MoNNoT, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented a certain new and useful Process of Making Compound MetalBodies; and I do hereby declare the following to be a full, clear, andexact description of the same, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to processes of makingcompound metal bodies andconsists in a'method of firmly and permanently welding together unlikemetals to form compound metal articles, such unlike metals comprising onthe one hand steel and ferrous metals, and similar iron-like metals suchas cobalt, nickel and the like, and on the other hand the high meltingnon-ferrous malleable and ductile metals like copper, silver, gold,aluminum, platinum and the like; all as more fully hereinafter set forthand as claimed.

It is a matter of common knowledge that it is practically impossible toweld together ferrous metals of the class which have a pronouncedaiiinity for carbon (for example, form carbids readily) with the unlikenonferrous metals of high melting ,point of the copper and noble metalgroups of metals having little or no affinity for carbon (for example,do not form carbidsreadily). For many purposes, however, ferrous metalbases coated with these relatively expensive, relatively inoxidizablemetals are desirable and many attempts have been made in the prior artto produce them. It is uite a common expedient. to attempt to ma e aunionl between these unlike metals by simply casting them together atthe ordinary casting tem! perature of the non-ferrous metals, but suchattempts have not been crowned with practical success, by reason of thelack of atlinity existing between such ferrous metals and suchnon-ferrous metals at the ordinary cast- -ing temperature of the latter.Quasi-unions have frequently been produced in which the two unlikemetals were, so to speak, merely stuck together, but not a union of thenature of a weld; a coherence as distinguished from an adherence. Suchcompound metal bodies therefore have always permitted ready separationof the .joined metals by mechanical force, temperature changes and thelike. A

cold chisel or similar cuttin finds and follows the line o junction, norwill' such articles withstand heating and quenching` in water.Co-extension yof the joined metals by rolling, wire-drawing, hammeringand the like have been frequently practiced to a certain degree; to anextentwherein the coating non-ferrous metal has still sufficientthickness to give it mechanical strength enough to support itself.

tool readily In other words, taking copper on steel, a Y

compound ingot made by the rior simple casting process would frequent yermit of co-extension to a certain extent, t e copper forming, so tospeak, a tubular shell around the steel core. When the extension,however, went beyond this point and the copper became a mere film, ofinsufficient thickness and strength for its own sup ort, it readilystripped from the wire. T is defect has precluded the manufacture ofrelatively thin film-like coatings upon steel objects to form finishedcoated articlesby relatively cheap large-scale processes and for suchcoated articles it is now the usual practice to coat each finishedarticle separately by electrolytic or like process. Electrolyticcoatings, however, when thin, readily exfoliate and at any thickness areorous, permitting ready permeation of ampness, gases -or other corrodingagencies to the underlying metal.

It is the purpose of the present invention to provide a simple cheap andready method of forming dense, hard impermeable weldedon coatings of theless oxidizable metals upon the described ferrous and similar metals.

. In other applications Sr. Nos. 281,680 and 333,570, I have describedand claimed broadly, methods of forming welded-on coatings of thecharacter described depending on the fact that the lack of affinitybetween ferrous and non-ferrous met-als at the ordinary castingtemperature of the latter, dis.- appears when said non-ferrous metalsare raised to a degree relatively high above their melting points, atemperature which I have called, for lack of other name, the supermoltencondition. The stated non-ferrous metals when in the supermoltencondition readily wet and combine with cleaned surface of ferrousmetals, producing a firm, permanent and indestructible union between thetwo metals, and when the liquid metal the contact of the supermolten cosolidies forinin a weld union which resists destruction or iscovery bycutting tools, which cannot be broken by violent temperature changes andwhich does not rupture along the line of 'unction uon. repeated ilexureof the join, metals t is, aswill be seen, a union similar in allcharacteristics to that roduoed-by a good weld between pieces ofpferrous metals, and I therefore call 1t a weld union withoutnecessarilycommitting myself to any theory as to its exact chemical orphysical. nature. It may be tlfiatr, or instance, produces a .tenuouslme alloy iilm of copper and steel u n the steel surface; it may bethatthe thinly uld copper, which is so fluid at the supermoltentemperature that it readily finds otherwise undiscoverable fissures andaws in the steel, flows molecularly into the intra-molecular lacunae onthe surface of the steel, producing, so to s ak, a molecularinterlocln'ng such as proba ly occurs in ordinary welding; and manyother plausible explanations are possible.

But I content myself with notingthe factl of the existence of the strongpermanent union described without committing myself as to theories ofits nat-ure. i A

I have now discovered that ,a union-of similar character may b'eproduced in a'differentway. If a mass of co per or non.- ferrous `metalof the kind escribed, be placed in an ingot mold of suitable shape, anda clean steel billet heated to what is called a dripping temperature (i.e.- the extreme White heat at which particles rom the surface of themetal begin to drip dowii,)

be contacted therewith, a similar union results, probabl becausetli'eintensely' heated steel raises t e tem erature of proximate layers ofcopper or tlie like to the necessary supermolten degree. It is of coursenecessary in this operation that the bulk of the coating metal, which isordinarily of high heat conductive capacity, be not so great as to cooldown the steel at the line or surface of union before the union can takeplace. However, the amount of coating metal (cop er, for instance)required to roduce coatings of the thickness ordinarl y desired, is-

not sufficient, when confined ina suitable ingot mold, to diminish 'the'temperature of the metals below the uniting point.

It is best to first clean preliminarily--the core or billet to be coated(usually a bar orv block of steel) which may be done advantageously bymeans of a sandblast or like mechanical means, followed, if desired, bypickling. The core or billet so prepared is then heated to the describedtemperature under circumstances precluding ox1dation, and when so heatedis transferred to the mold containing the coating metal, und'ercircumstances precluding oxidation. But the preliminary cleaning isnotnecessary inall surface once clean 'cannot become contami--electrolytically, the stated acids bein :Haase cases because owing tothe high temperature to which the hina or core is heated the outer layerwill be, or may be, melted off, thus carrying awa. the usual layer ofscale or oxid on the sur ace of iron and steel, and exposing a cleanmetallic surface; and since theheating and transfer of the core to thecoating metal are both conducted under circumstances precludingoxidation or other contamination, as hereafter described, the

nated a in. The low -heat conductivity of steel a ows the surface to beraised to or nearly to a melting temperature before the interior becomesdangerously soft. With the surface at a dripping heat any scale or oxidwhich may be present drips olf leaving a clean metallic surface and whenthis clean, dripping billet is raised into an atmosphere of producergas, as it preferably is, it cannot become 're-oxidized as itssuperficial temerature lowers, the producer gas indeed reucing anyoxidwhich may form. When pickling is resorted to, as it may be at timesnevertheless, it is best performed with an acid 'ving an`iron compoundreadily volatiliza le such as hydrochloric or h drofluoric acid.Pickling may ofcourse done enerated on the core or billet to be oleanesed as an anode in an electrolyte of a suitable salt solution. Thehighly heated core or billet havin been transferred to the ingot moldcontaining the molten coating metal, is immersed in the molten metal andiscarefully centered or otherwise located. in its predetermined positionin the mold, and the molten metal is allowed to solidify thereon. Theconditions under which the operation is carried on are 105 su'ch that,knowing as I do that the coating metal is capable of reaching theso-'calledsupermolten condition at a temperature. lower than that of thecore or billet when immersed in the molten metal, it is reasonablepreviously heated to such supermolten tem- 120 ,perature, as describedin my aforementioned applications.

While I am not limited to the use of any particular apparatus forcarrying out my saidvprocesam the accompanying drawings I haveillustrated certain apparatus suitable and'convcnient for the purpose.

In said drawings: Figure 1 shows diagrammatically in sectional elevationa heating -furnace `for the cores or billets, with ,130

v lets from oxidation or other contamination while in transit and whilebeing immersed in the coating metal. Fig. 2 shows a detail elevation andpartial vertical section of one form of such hoisting, conveyingandprote'cting apparatus. Fig. 3 shows a vertical section of thecomplete ingot mold with a core therein.` Fig. 4 shows a detailelevation and partial section of an alternative form of hoisting andprotecting apparatus; Fig. 5 a detail vertical section, on a largerscale, of the gripping mechanism thereof and of the protective casing,and Fig. 6 shows a detail transverse horizontal section through thelower part of such casing, indicating means for centering and guidingthe upper end of the billet.

In said drawings, 1 indicates a suitable heating furnace and 2, 2indicate cores or billets being heated therein. Said furnace has in itsroof openings 3 normally closed by two-part covers 4. Each such billethas screwed into its upper end a short porter bar `5 provided with aguide and centering disk 6; and as indicated particularly in Fig. 2,each such disk is tapped from its upper side to permit a second andlonger porter bar 7, forming part of the hoisting and conveyingapparatus, to be screwed therein. ter bar 7 is weighted, for a reasonhereinafter disclosed, and is suspended by means of a cable 8 from asuitable power hoist 9 mounted upon a wheeled truck 10 arranged to moveupon a track 11. Surrounding this bar 7 is a casing 12 suspended bycables 13 from a hoist 14 mounted upon the same truck 10. This casing isopen at the bot-tom, is adapted to receive through its bottom opening,and to contain, the billets 2, and is provided with means, such as apipe 15 and valve 16, for supplying to it a non-oxidizing or indifferentatmosphere, such as producer gas made from charcoal and containing nomarsh gas or other decomposable hydrocarbons.

The inolten coating 4 metal is contained within an ingot mold 17, suchfor example as shown in Fig. 3, adapted to receive the lower end of thecasing 12, which latter then forms practically a continuation of theingot mold.

In the construction shown in Fig. 3, said ingot mold consists of a base18 and cylindrical upper portion 19 of the saine internal diameter asthe casing 12, and a collar 20 adapted to receive the lower end of saidcas- 'ing 12 and make a tight joint therewith.

Said por? When one of the billets 2 has been heated in the furnace 1 toa suitable temperature, the hoisting and conveying'a parat-us is movedover it, the porter bar 7 Eiwered and screwed into the guide-disk 6, andthen the casing 12, filled with the protective atmosphere as aforesaid,is lowered down to the two-partk cover 4, thesections of said coverseparated sufi'iciently to permit the billet to be raised, and then saldbillet is raised quickly into the casing 12, after which the sections ofthe cover 4 are re laced, the casing 12 is raised with the billet withinit, and the whole conveying apparatus with the billet within the casing12 1s moved over the in ot mold 17, which has previously been fil edwith a quantity of molten coating metal, at suitable temperature, justsuiiicient to form the desired coating. In the case of copper or othei`coating metal which when molten is readily oxidizable, the molten metalis poled or treated with charcoal or a silicon compound to remove anytrace of oxid, and its surface is then preferably covered with ux toexclude air.

The casing 12, with the ingot or billet 2 lwithin it, having beenbrought directly over said in ot mold 17, said ingot mold and billet areowe/red together until the lower end of said casing lits within collar20 and makes a tight joint with the ingot mold, forming, in tact', anupward continuation thereof. The billet 2 is then lowered to the bottomof the ingot mold, the molten metal rising as it is displaced, andfilling the casing 12 to the top of the billet or other desired level;the vent 21, if provided, being closed as this is done. The lowerportion of the ingot mold is provided with suitable means for centeringthe-lower end of the billet-for example, is made conical or tapering.The casin 12 is centered with respect to the ingot mold by the collar20, andthe upper end of the billet is centered within the casing 12 bythe disk 6. Accurate centering of the billet with reference to thecoating to be formed is thereby insured. That the eXtreme lower end ofthe coated billet will be tapering, owing to the taper of the lowerportion of the mold interior is unimportant, as in the rolling to whichthe ingot is subsequently'subjected the coating will be spread so as togive equal thickness of coating throughout.

The molten metal having solidified around the ingot or billet sointroduced into it, the coated ingot is forced out of the casing 12, andthe latter is ready for use again; the operation having meanwhile beenrepeated numerous times with other casings and other ingot molds,-thehoists 9 and 14 being readily detachable from the casings 12v and porterbars 7, as shown.

The function of weight 22 on porter bar 7 is to force the billet downinto the molten coating metal in case, as may often happen,

i the metal of the billet is of less specific gravity than the moltencoatin metal. The casings 12 have weighted hea s 23 for the same reason.

In Fi 4, 5 and '6 I illustrate alternative means or raising and loweringthe ingot orbillet to be coated, whereby tap in of the said billet atthe to to receive t e s ort porter bar 5 is avoid In this construction,24 having gripping jaws 25 ada ted to grip and hold the billets 2. Thiscliuck is suppassing through packed orifices in the head of the casing,(thou h packing around these rods is not strict y necessary, as someleakage of the protective atmosphere around these rods is notobjectionab e) and at the top are connected to a slide 26 mounted inguides 27 in the truck 10 and provided with means for raising andlowering it-for example, a rack-bar 28 engaging a pinion 29 on the shaftof a hoisting motor 30. The slide 26 is rovided with a cylinder 31 andpiston 32, t e piston rod 33 of which projects through the head ofcasinported by rods 25'- 12 and is provided with a collar beneathv anVslapping adapted to engage and o erate the bell-crank aws 25. Va ves 34and 35 are provided or admitting iuid under pressure above and below thepiston 32 at will, and for permittin exhaust, as is common in pneumatican hydraulic and like Huid-pressure hoists. So long as piston 32 pullsupward, it keeps the jaws 25 in gripping contact with the billet, andprevents slipping of the latter from said jaws. If the pressure belowthe piston 32 be relieved, said jaws are no longer held closed, and theweight of the bil et will cause them to. release said billet; s rings 36being provided,

if desired, to faci itate or hasten release of billet.' Iressure abovepiston 32 will cause the rod 33 to engage the top o f the billet andforce the same out of the jaws 25, if necessary, or force the billetdown into the molten metal in the ingot mold. In this construction, thecasing is best formed of relatively separable sections, 3 7 and 38, asshown, normally held together by convenient latches 39, and the upperend of each section 38 is provided with centering lugs 40, as shown inFig. 6; the intention being that when the billet is pushed clear down tothe bottom of the ingot mold and the molten .metal has risen around it,said molten metal will come just to the topv of the billet and to saidcentering lugs 40, and just below the joint between the upper and lowersections 37 and 38 of casing 12.

It will be obvious that the process and apparatus herein described areapplicable to the coating of billets or cores of any desired.cross-section, whether round, square,

` elongated in one direction (rectan lar, for

example) or irregular shape; an likewise I provide within the casing achuck lconvenient means to non-ferrous metals desi that the ingot moldmay be of any desired Y cross-section. This process and apparatus aretherefore particu arly suitable for producing coated slabs, plates, etc.The coating metal-` not being heated to the su rmolten temperature priorto the introse tion of the articlel to be coated therein, is not sosubject to oxidation, contamination or deterioration as is su rmoltenmetal, and is not so likely to absor or dissolve and become contamlnatedwith the metal of the core or base coated; a matter of such moment whenelectrical conductors, for exam' ple, are to be produced. v

The various coating metals which I particularly contemplate using,l forexam le, copper, silver, go d, aluminum, copper allldys such as brass,bronze aluminum bronze, etc.,

are all high melting ductile metals which can be worked with steel atsteel working temllc- Y peratures and all have Amelting temperaturesabove 500 C.; and it is deslrable in most cases `that the coating metalshall be one having a melting temperature above 900 F., since steelreuires to be heated above such temperature or forging and hot-workinggenerally. Hence such temperature forms a distinguish such metals as Iparticularly contemplate using from metals of low melting point such aslead and tin which cannot be worked with steel at steel workingtemperatures. I have used the term ferrous metal to designate pure iron,iron (such as may be ma e, for example, by the Tropenas rocess), wroughtiron, steel of various gra es, including Various compound steels, suchas nickel steel, chrome steel, titanium steel, etc. The term ates theunlike metals, such as copper, si ver, gold, platinum, aluminum, etc.,to be used preferably as coating metals. The supermolten temperature ofcopper, as nearly as I have been able to determine it, is around andabove 2500 F.; that of silver is in the same neighborhood; that of goldsomewhat higher, and that of aluminum somewhat lower. The drippingtemperature of iron or steel varies somewhat carbon in the steel andother well-known conditions, but is in every case, so far as I accordingto the amount ofI am aware, much above these supermolten temperatures.

.1. The herein described process 'of welduniting unlike metals, whichcomprises heating a body of one such metal to a high white heat farabove the melting temperature of the other metal under circumstancesygiving a clean'metallic surface to said body, -immersing said body soheated in a molten mass of the other such-metal and causing such moltenmass to solidify thereon.

2, The herein described process of welduniting unlike metals, whichcomprises heat'- comprises heating a body of ferrous meta-l ,i

ing a body of one such metal' to a temperature above the supermoltentemperature of the other metal under circumstances giving a cleanmetallic surface to said body, immersing said body so heated in a moltenmass of the other such metal and causing such molten mass to solidifythereon.

3. 4The herein described process of Welduniting ferrous metals andnon-ferrous metals having melting temperatures above 900 F., whichcomprises heating a body of ferrous metal to a high White heat far abovethe melting temperature of such non-ferrous metal under circumstancesgiving a clean metallic surface to said body, immersing said body soheated in a molten mass of such non-ferrous met-al and causing suchmolten mass to solidify thereon.

4. The herein described process of welduniting ferrous metals andnon-ferrous metals having melting temperatures above 900 F., Whichcomprises heating a'body of ferrous metal to a temperature above thesupermolten temperature of such non-ferrous metal under circumstancesgiving a clean metallic surface to said body, immersing said body soheated in a molten mass of such non-ferrous metal and causing suchmolten mass to solidify thereon.

5. The herein described process of Welduniting ferrous metals andcupriferous metals having melting temperatures above 900 F., whichcomprises heating a body of ferrous metal to a temperature above thesupermolten temperature of such cuprifer-V ous metal under circumstancesgiving a clean metallic surface to said body, immersing said body soheated in a molten mass of such cupriferous metal and causing suchmolten mass to solidify thereon.

6. The herein described process of weldunitin ferrous metals and copper,which .in the presence of two witnesses.

to a temperature above the supermolten temperature of=`copper undercircumstances givlng a clean meta lic surface to said body,

immersing saidbody so heated in a molten mass of copper and causing suchmolten mass to solidify thereon.

7. The herein described process of Welduniting ferrous, metals andnon-ferrous j metals having melting temperatures above 900 F., whichcomprises heating a body of ferrous metal to a high White heat undercircumstances giving a clean metallic surface to said body, immersingsaid body so heatedin a molten mass of such non-.ferrous l metal andcausing such molten mass to 4the melting temperature of the non-ferrousmetal under conditions precluding oxidation, transferring said body offerrous metal so heated, While surrounded with a protective atmosphere,toa molten Vmass of such non-ferrous metal, and'then immersing said bodyso heated in such vmolten mass and causing such mass to solidi thereon.

In testimony whereof I a my signature,

JOHN F. MONNOT. Witnesses:

JAS. K. CLARK,

